This invention relates to a gasket particularly but not exclusively intended for sealing the joint between the cylinder block and the cylinder head of a dry liner internal combustion engine.
In my co-pending British Patent Application No. 7 940 625 and its corresponding U.S. Pat. No. 4,290,616 there has been proposed a gasket which comprises a pair of outer metal plates having outwardly directed corrugations formed therein and a central composite metal plate disposed between the two outer plates, the said central plate comprising a central soft metal layer and hard metal surface layers which are bonded or integral therewith. That gasket was characterised in that it incorporated around each cylinder bore opening a sealing washer formed on each axial face with circumferential serrations of V-shaped profile, the thickness of the washer measured over the peaks of the serrations being somewhat greater than that of the composite spacer plate whereas the thickness measured between the troughs of the serrations was significantly less than that of the spacer plate.
However in performing a test programme on certain engines equipped with these gaskets it was found that the quality of the metal necessary for sealing the water and oil apertures between the cylinder head and the cylinder block was unsatisfactory for the gas seal around the cylinder bores, the metal suffering very badly from thermal fatigue because of the ambient temperature pressure.